量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果（学会誌発表論文、学会発表、研究開発報告書、特許等）を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum and Radiological Science and Technology.

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In order to evaluate the environmental behavior of contaminants such as radionuclides, we collected soil samples throughout Japan and measured their characteristics. The characteristics include CEC, soil pH, exchangeable Ca and K, concentrations of major elements (e.g., Al, Fe, Mg and Mn) and trace elements (e.g., Cs, Se, Co, Th and U). The soil-soil solution distribution coefficients (Kds) of some radionuclides were also determined in our institute.
Using these data sets, a mapping system to show distributions of elements, radionuclides and related data (e.g., CEC, pH and Kd) in soil was developed, which is called as MdsoiL. MdsoiL is a set of databases of soil characteristics data and a mapping system to make contour maps of the data using inverse distance weighting to visualize the geographic distribution of the data. For example, the contour map of Kd values for Se (Kd-Se) is made without obtaining Kd-Se data for all Japanese soils to evaluate the mobility of Se in Japanese soils. The Kd value is defined as concentration of an element in or on the soil solid phase divided by concentration of the element in the soil solution. The contour map showed that the Kd-Se was higher in Kyushu, Kanto and Tohoku districts than those in Tyugoku, Shikoku and Kansai districts. This trend corresponded with the geographic distribution of volcanic ash soil. It is known that the Se sorption level is relatively higher in volcanic ash soils than other soil groups in Japan, because volcanic ash soils contain large amounts of active Al. Subsequently, the Se mobility differences among districts were clearly observed due to the geographic distribution of soil types. Thus, MdsoiL is a useful tool to evaluate environmental behaviors of contaminants.